Numerous devices have already been described for fixing a casing to a support bar having parallel rims in particular by means of resilient fixing tabs. Now, in an installation, circumstances sometimes lead to the use of several types of support bars; it is then desirable for the fixing arrangement of a single casing to be adaptable to several of these types of bar and more particularly to a bar having inwardly turned rims as well as to a bar having outwardly turned rims.
For this purpose, fixing arrangements have been contrived which comprise four fixing tabs, two of which are used for fixing to one type of bar and the other two of which are used for fixing to another type of bar. But such arrangements lead to fairly complex configurations and generally to fixing at different heights in relation to a reference edge of the support bar.
Preferred embodiments of the present invention enable a terminal block to be fixed to two different types of support bar (one having inwardly turned rims for engaging the block the other having outwardly turned rims) with the block extending to the same height from a reference rim in both cases.
The present invention provides a structural arrangement for fixing a casing to a support bar having parallel rims, said bar being one or other of two different types of bar, one type having rims turned outwards and the other type having rims turned inwards, the casing comprising a base having a flat at one side thereof which bears on one of the rims of a bar (of either type), said flat being flanked on its outer side by a first resilient fixing tab which includes a resilient lock notch at the level of the flat and on its inner side by a second fixing tab which includes a rigid fixing notch at the level of the flat, the end of said rim co-operating with one or other of these notches depending on the type of the bar, while on the other side of the casing, the end of the other rim co-operates simultaneously either with a rigid fixing notch disposed at the root of a third fixing tab or with a resilient lock notch disposed at the end of said third resilient tab.
Preferably, a recess is provided between the flat and the second fixing tab at the root of the fixing notch, the third fixing tab possibly including a vertical slot at its root.
The casing may include a second bearing flat at the level of the rigid fixing notch between the second fixing tab and the third fixing tab.
An embodiment of the invention is described by way of example with reference to the accompanying drawing.